Apparatus for continuously making an endless wafer laminate of uniform width, consisting of individual wafer sheet layers and intervening cream layers

ABSTRACT

Process and apparatus for continuously making an endless wafer laminate which has a uniform width and consists of individual wafer sheet layers and intervening cream layers. In order to increase the production rate of such wafer laminate while maintaining a high quality, the invention teaches that each edge of the wafer sheets for the lowermost wafer sheet layer is registered and the deposition of the wafer sheets for the remaining wafer sheet layers is controlled by the succession of said wafer sheet edges. The butt joints of the wafer sheets in the individual wafer sheet layers are offset relative to each other in the direction of conveyance or are arranged exactly in register. For registering the wafer sheet edges, the edges of consecutive wafer sheets are displaced or pivotally moved relative to each other or pulled apart to form a gap. Each wafer sheet for the additional wafer sheet layers is moved to a waiting position in the wafer sheet applicator, which succeeds the coating head for applying a cream layer, and in dependence on the succession of the wafer sheet edges of the lowermost wafer sheet layer is applied to the adjacent cream layer and is then forced against the same. The resulting wafer laminate is used as an intermediate product for making small wafer slices.

This is a division of our copending application Ser. No. 432,931, filedSept. 29, 1982, now U.S. Pat. No. 4,518,617.

This invention relates to an apparatus for continuously and particularlyfully automatically making an endless wafer laminate of uniform width,consisting of individual wafer sheet layers and one or more compositionlayers, preferably cream layers.

Various baked wafer products made by machine are known, inter alia, inthe food-processing industry. These baked wafer products are placed onthe market in a filled or unfilled state and are generally known asluxury foods. Such products of the wafer-baking industry are, e.g.,wafer cones, wafer cups, wafer plates, flat wafer discs, low hollowwafers, hollow sticks, wafer rolls, icecream cones, filled wafers,icecream wafers, small filled wafer sticks, wafer slices and the like.These baked wafer products made by baking a wafer dough are crisp andbrittle and break easily. They are baked to be as dry as possible andhave a very low moisture content.

The various baked wafer products can be made in various ways. Some waferproducts are baked in their final shape. This applies, e.g., to wafercones, wafer cups, wafer discs, low hollow wafers and the like.

In the manufacture of other baked wafer products, a wafer sheet or anendless wafer strip is baked first and is given its final shape when itis still soft after the baking operation. In that final shape the bakedwafer product is permitted to cool and to assume a crisp and brittleconsistency. Examples of such baked wafer products are sugar-containingicecream cones, hollow sticks, sugar-containing wafer rolls and thelike.

Other kinds of baked wafer products are made in that a plurality ofwafer sheets are baked, cooled, coated with cream, and stacked to form awafer block. That creamfilled wafer block is subsequently cut into smallhandy pieces of uniform size, which are then packaged in unitsconsisting of one or more pieces, possibly in vacuum packages, and areplaced on the market in that form.

Various baked wafer products may be provided with coating consisting,e.g., of sugar or chocolate, or may contain various filling materials,such as icecream, various others creams, chocolates or the like.

The wafer products described hereinbefore differ from waffles, which areusually baked by housewives in waffle irons and constitute a soft bakedproduct, which is similar to rolls or pancakes. These waffles made byhousewives do not resemble at all the above-mentioned baked waferproducts of the wafer industry as regards consistency and use.

Those industrially made wafers which are baked in their final shape,such as wafer cones, wafer cups, wafer figures and the like, on the onehand, and individual wafers, which are coated with cream andsubsequently assembly to form a wafer product, such as flat wafers,wafer sheets, shallow hollow wafers, or the like, on the other hand, aremade in automatic wafer-baking ovens.

In the making of small cream-filled wafer slices which are sold as slicepackages, in which a plurality of wafer slices are juxtaposed and/orarranged in a row, it is known to form a blocklike intermediate productby assembling the wafer sheets which have come from an automaticwafer-baking oven and coated with cream. Such an intermediate product isconstituted by the wafer blocks or wafer books made on wafersheet-coating machines. Another intermediate product of that kind isconstituted by an endless wafer laminate, which consists of individualwafer sheet layers and intervening cream layers and in which the severalwafer sheets are arranged in bond like bricks in a masonry wall so thatsaid wafer laminate can be described as a bondtype wafer sheet laminate.

In the making of wafer blocks it is known from Austrian PatentSpecification No. 329,479 to provide a plurality of wafer sheetapplicators above a common conveyor belt and to provide a coating headbetween adjacent wafer sheet applicators. The conveyor belt hasprotruding tines, which are higher than the wafer block to be formed andhave a spacing which exceeds the length of the wafer block. In eachwafer sheet applicator a wafer sheet is pulled out of a wafer sheetmagazine at the lower end thereof and is introduced into a calibrateddowncomer, which terminates above the conveyor belt and in which eachwafer sheet slowly descends in a substantially horizontal orientation toa receiving bottom of said downcomer, and is subsequently pulled fromsaid receiving bottom by the tines of the conveyor belt so that thewafer sheet then lies between two successive rows of tines on theconveyor belt or on cream-coated wafer sheets previously applied to saidbelt. Each of these wafer sheets is separated from the preceding andsucceeding wafer sheets by respective rows of tines. A first coatinghead then applies a cream coating in a film-coating process on each ofthese wafer sheets. In the next wafer sheet application each row oftines removes a wafer sheet from the downcomer in the manner describedhereinbefore so that said wafer sheet comes to lie on the cream coatingof the next lower cream-coated wafer sheet and is aligned with thelatter only by the rows of tines. These wafer sheets are then forcedagainst the cream coating by a pressure roller. These process steps arerepeated until a wafer block having the desired number of layers hasbeen formed. As a result of the process, a series of water blocks whichare provided with cream layers and separated by rows of tines are formedon the conveyor belt.

In that known process the time required to form each wafer block dependson the time required for the movement of each wafer sheet from the wafersheet magazine through the downcomer onto the cream coating on the nextlower cream-coated wafer sheet because only a single wafer sheet can beintroduced into the downcomer at a time after the preceding wafer sheethas reached the bottom of the downcomer. The wafer blocks are thenprocessed to form individual wafer slices having a predetermined lengthand width and the same height as the wafer blocks. For this purpose thewafer block is severed. Owing to the size ratio of the wafer slice tothe wafer block, only a certain number of wafer slices can be cut from awafer block and narrow marginal portions which constitute waste remainat all edges of the wafer block in a size which depends on the size ofthe wafer slices.

In connection with the making of a wafer laminate consisting of aplurality of wafer sheet layers and intervening cream layers,particularly a bond-type wafer sheet laminate, it is known from GermanPatent Specification No. 948,864 that the wafer sheets baked in standardsize in an automatic wafer-baking oven can be applied by hand orautomatically on a table or a supporting conveyor element to form aseries of longitudinally and, if desired, transversely abutting wafersheets, which then constitute a wafer sheet layer of uniform width. Alayer of filling material can then be applied in a conventional mannerto the resulting closed wafer sheet layer and another wafer sheet layercan be applied by hand on said filling material layer in a third processstep. The joints in the upper wafer sheet layer are staggered from thosein the lower layer like the joints between bricks in a masonry wall. Toform a wafer laminate or bond-type wafer laminate having a plurality offilling material layers, another layer of filling material is applied tothe uppermost wafer sheet layer and is covered with a new wafer sheetlayer. These process steps are repeated until filling material layers inthe desired number have been formed. To perform that known process, eachcoating device is succeeded in the direction of travel of the conveyorbelt by a worker, by whom consecutive new wafer sheets are applied toand forced against the layer of filling material. That process has thedisadvantage that the application and forcing by hand requires specialcare and attention by the workers and nevertheless a relatively largequantity of waste will be obtained if the wafer sheets are notsuperimposed in exact register or are not uniformly forced down. Theproductive capacity is very low because the velocity of the belt islimited by the ability of the worker and the time required for theapplication by hand. There is a frequent breaking of individual wafersheets, particularly at the edges and corners.

It is an object of the invention to avoid the disadvantages which havebeen pointed out and to provide an apparatus which permit a continuousmaking of a wafer laminate of uniform quality at a high production ratewithout any manual contact with the wafer sheet.

In our copending application, we have claimed a process for thecontinuous and particularly fully automatic making of an endless waferlaminate of uniform width in that individual wafer sheet layers and oneor more composition layers, particularly cream layers, are superimposed,wherein a first lowermost wafer sheet layer consisting of individual,consecutive wafer sheets is formed first on a conveyor belt or the like,on which adjacent edges of said wafer sheets preferably adjoin,whereafter a composition layer is applied to the previously formed wafersheet layer and another wafer sheet layer consisting of a plurality ofconsecutive wafer sheets, the adjacent edges of which preferably adjoineach other, is applied to and subsequently forced against saidcomposition layer, until the desired number of wafer sheet layers andcomposition layers has been obtained, and wherein the uppermost wafersheet layer of the wafer laminate is also provided with a compositionlayer, if desired, which process is characterized in that the individualwafer sheets for the first, lowermost wafer sheet layer are successivelysupplied to the conveyor belt in a row, one edge of each wafer sheet,which edge extends transversely to the direction of conveyance, isregistered by a sensor, each wafer sheet for each additional wafer sheetlayer is moved to a waiting position disposed above the uncovereduppermost composition layer of the previously formed portion of thewafer laminate, and each wafer sheet remaining in its waiting positionis dropped onto the uppermost composition layer, possibly with a delay,when the sensor registers an edge of the wafer sheets for the first,lowermost wafer sheet layer.

The process according to the invention permits the making of acontinuous endless wafer laminate at a high production rate, which ismuch higher than would be possible if the wafer sheets were applied byhand. The resulting wafer laminate has a much more uniform structurebecause the succession of the several wafer sheets in each wafer sheetlayer depends on the succession of the wafer sheet edges of the wafersheets for the first, lowermost wafer sheet layer, which edges areregistered by the sensor. This will result in a highly precisesuccession of the several wafer sheets in such a manner that the leadingedge of each wafer sheet closely succeeds the trailing edge of thepreceding wafer sheet and this is accomplished without a need for atouching of the wafer sheets with the hand. Another advantage affordedby the process according to the invention resides in that the individualwafer sheets of each additional wafer sheet layer are uniformlydeposited on the next underlying composition layer so that the wafersheet joints in each wafer sheet layer are provided in a uniformsuccession throughout the length of the resulting wafer laminate likethose of the first wafer sheet layer.

Another advantage of the process according to the invention resides inthat the wafer laminate must be trimmed only at its longitudinal edgesduring its further processing.

According to a further feature of the invention a process particularlyfor making an endless bond-type wafer sheet laminate, is characterizedin that the wafer sheets for at least one of the additional wafer sheetlayers are dropped from their waiting position onto the underlyingcomposition layer only when the leading edge of that wafer sheet of thefirst, lowermost wafer sheet layer which corresponds to the wafer sheetto be dropped, which remains in waiting position, has moved past thevertical projection on the conveyor belt of the leading edge of thewafer sheet which remains in waiting position so that the wafer sheetwhich has been dropped from the waiting position will lie on theadjacent composition layer in a position in which said dropped sheet isspaced from the associated wafer sheet of the first, lowermost wafersheet layer by a distance which corresponds at least to the distancewhich corresponds at least to the distance of fall. This ensures thatthe joints between the wafer sheets in each additional wafer sheet layerwill be arranged with a precise, uniform spacing, which corresponds tothat in the first wafer sheet layer, and said spacing of the wafersheets of the respective wafer sheet layer from those of the first,lowermost wafer sheet layer will be maintained throughout the length inwhich the wafer laminate is made.

The bond-type wafer sheet laminate may be cut into individual endlesswafer bars, to which, e.g., nougat compositions, Turkish delight or thelike may be applied. The thus coated wafer bars are then cut intoindividual pieces having a predetermined length and may then be coated,e.g., with chocolate. The bond-type endless wafer sheet laminate whichis made continuously in accordance with the invention affords a numberof advantages in the further processing. For instance, less waste isobtained. The product length in the direction of conveyance is notlimited and can easily be altered at any time; such alteration will notincrease the waste.

According to a further feature of the invention a wafer sheet which isin waiting position and intended for an additional wafer sheet layer isdropped only after an interval of time which corresponds to its spacingfrom the wafer sheet in the lowermost wafer sheet layer.

If the process is carried out in that manner, the place at which thecomposition layer is applied to each additional wafer sheet layer can beselected independently of the spacing of the wafer sheets of that wafersheet layer from the wafer sheets of the first, lowermost wafer sheetlayer so that the several composition layers can be applied to theadditional wafer sheet layers in a quicker succession or in anothersuccession than would correspond to the spacing of the wafer sheets ineach wafer sheet layer from each other and from the first, lowermostwafer sheet layer.

According to another feature of the invention a process particularly formaking an endless series of wafer blocks connected to form an endlesswafer laminate is characterized in that the wafer sheets remaining intheir respective waiting positions and intended for the additional wafersheet layers are deposited on the adjacent composition layer of thepreviously formed portion of the wafer laminate substantially inregister with the associated wafer sheets of the first, lowermost wafersheet layer so that the wafer sheet joints of the several wafer sheetlayers are in register. In that process, individual wafer sheets joinedonly by the composition layers disposed between the wafer sheet layersand, if desired, by webs of composition forming in the registering wafersheet joints can be made in an endless sequence to form an endless waferlaminate so that a much higher number of wafer blocks can be obtained ata given production speed than in the known wafer sheet-coating machine,in which one wafer block is made after the other.

According to another feature of the invention, each additional wafersheet layer is formed in that each wafer sheet intended for that wafersheet layer is first applied to the adjacent composition layer in such amanner that a gap is left between the leading edge of that wafer sheetand the trailing edge of the preceding wafer sheet and the wafer sheetis subsequently displaced on the composition layer until the gap isclosed and the leading edge of the wafer sheet adjoins the trailing edgeof the preceding wafer sheet. In that process, an overlap of theadjacent edges of successive wafer sheets in a given wafer sheet layeris prevented and a contact between successive wafer sheets will beensured even if the wafer sheets differ in length in the direction ofconveyance so that length differences between wafer sheets will becompensated.

According to a further feature of the invention the wafer sheets for thefirst, lowermost wafer sheet layer having adjacent edges adjoining eachother are first guided in a layer which is offset across the directionof conveyance from the path of the complete wafer laminate and are thenlaterally displaced into the path of the complete wafer laminate so thattwo consecutive wafer sheets are laterally offset from each other andone of the two adjoining wafer sheet edges protrudes laterally from theother, and at least one sensor registers the protruding portion of oneof the two wafer sheet edges. That guidance of the wafer sheets for thefirst wafer sheet layer ensures that the leading and trailing edges ofthe wafer sheets will adjoin each other as the wafer sheets areconveyed, that the successive wafer sheet joints will be reliablyregistered by the sensor before the composition layer is applied to thefirst wafer sheet layer and an exact succession of the wafer sheetswhich are deposited in the other wafer sheet layers on the respectivecomposition layer is also ensured.

Another variant of the process according to the invention ischaracterized in that the wafer sheets for the first, lowermost wafersheet layer are first guided in the plane of conveyance of the completewafer laminate while their adjacent edges adjoin, and the individualwafer sheets are then successively lifted from the plane of conveyanceof the complete wafer laminate so that the wafer sheet lifted in partfrom the plane of conveyance is turned or displaced at right angles tothe direction of conveyance at least at one of its edges which adjoinedges of the adjacent wafer sheets.

It will be of advantage that that portion of the edge of a given wafersheet which has been turned or lifted from the plane of conveyance canbe reliably detected by the respective sensors whereas the wafer sheetneed not be removed in the direction of conveyance from the adjacent andadjoining wafer sheets.

For a detection of the edges of each wafer sheet, the invention callsfor the generation of a narrow, wedge-shaped gap between two consecutivewafer sheets. This is accomplished in accordance with the invention by aprocess variant which is characterized in that the wafer sheets for afirst, lowermost wafer sheet layer are first guided in the plane ofconveyance of the complete wafer laminate at an acute angle to the pathof said laminate and are then individually turned into the path of thecomplete wafer laminate and guided in said path with adjacent edgesadjoining each other only two consecutive wafer sheets are turnedrelative to each other so that a narrow, wedge-shaped gap is formed, andat least one sensor registers one of the two wafer sheet edges whichdefine the wedge-shaped gap.

In another variant of the process according to the invention the wafersheets for the first, lowermost wafer sheet layer are first guided sothat they are offset in height from the path of the complete waferlaminate and are then individually displaced in height into the path ofthe complete wafer laminate so that the adjoining wafer sheet edges oftwo consecutive wafer sheets are vertically spaced apart, the wafersheets are then guided in the path of the complete wafer laminate withtheir adjacent edges adjoining each other and at least one sensorregisters the trailing edge of the wafer sheet which has already beendisplaced in height or the leading edge of the wafer sheet which has notyet been displaced in height.

Two consecutive wafer sheets can be upwardly or downwardly displacedrelative to each other. An upward displacement will be desirable if thetrailing edge of the lifted wafer sheet is to be registered by therespective sensor. The lowering of the wafer sheet permits theregistering of the leading edge of the wafer sheet which has not yetbeen lowered.

Another variant of the process according to the invention ischaracterized in that the wafer sheets for the first, lowermost wafersheet layer are first conveyed in the path of the complete waferlaminate at a higher speed than the complete wafer laminate and arespaced appart in the direction of conveyance as they are thus conveyedand before the application of the composition layer are braked untilthey form the first, lowermost wafer sheet layer, in which theiradjacent edges adjoin, each wafer sheet arrives at the trailing wafersheet of first, lowermost wafer sheet layer and the trailing edge ofsaid just arriving wafer sheet is registered by at least one sensor.That variant will be of special advantage if the spacing of the wafersheets for the first, lowermost wafer sheet layer substantiallycorresponds to the difference between the velocities of conveyance ofsaid first, lowermost wafer sheet layer and of the complete waferlaminate.

According to another feature of the invention, the wafer sheets for thefirst, lowermost wafer sheet layer are first conveyed in succession andin spaced apart relation at a higher speed than the complete waferlaminate, said wafer sheets are then braked until their adjacent edgesadjoin so that the wafer sheets form a queue, whereafter only theleading wafer sheet of said queue wafer sheets is accelerated for ashort time so that a gap is formed between said leading wafer sheet andthe next succeeding wafer sheet, the accelerated wafer sheet is movedfaster than the queue of wafer sheets, and before the application of thecomposition layer those wafer sheets which move faster than the queue ofwafer sheets are braked until they form the first, lowermost wafer sheetlayer with their adjacent edges adjoining, wherein each acceleratedwafer sheet arrives at the trailing wafer sheet of the first, lowermostwafer sheet layer, and at least one sensor registers the leading edgeand/or the trailing edge of each accelerated wafer sheet or the trailingedges of that wafer sheet which is just arriving at the trailing wafersheet of the first, lowermost wafer sheet layer, or the leading edge ofthe queue of wafer sheets.

That process variant affords the advantage that the individual wafersheets can space any desired distance apart because any fluctuation inthe feeding of the wafer sheets will be compensated. In the making of abond-type wafer sheet laminate, another advantage resides in that theextent to which the wafer sheet joints in all additional wafer sheetlayers are offset from those in the first, lowermost wafer sheet layercan be adjusted as desired by the selection of the acceleration.

According to another feature of the invention, the accelerated wafersheets are moved at the same speed as the wafer sheets for the first,lower wafer sheet layer, which are spaced apart as they are conveyed ata higher speed than the complete wafer laminate.

According to another feature of the invention, the braked wafer sheetsof the queue of wafer sheets are moved at the same speed as the completewafer laminate. This will ensure that the feeding of the wafer sheetwill correspond exactly to the progressive formation of the waferlaminate.

For an exact control of the deposition of the wafer sheets of each wafersheet layers, the invention teaches that the wafer sheets supplied forthe first, lowermost wafer sheet layer move in succession past aplurality of sensors, which are associated with respective waitingpositions for the wafer sheets of the additional wafer sheet layers, andthe wafer sheet remaining in waiting position is not dropped onto theadjacent composition layer until the sensor associated with that waitingposition registers an edge of the wafer sheets for the first, lowermostwafer sheet layer.

To avoid an adverse effect on the sequences of wafer sheets by damagedwafer sheet edges, it is a feature of the invention that the wafersheets supplied for the first, lowermost wafer sheet layer move past aplurality of juxtaposed sensors, which register in each wafer sheet anedge thereof which is transverse to the direction of conveyance and areassociated with all waiting positions.

A further feature of the invention resides in that the leading edges ofthe wafer sheets are registered by sensors and the wafer sheetsremaining in the respective waiting positions are dropped, preferably atthe same time, when one of the sensors registers as the first sensor theleading edge of a wafer sheet for the first, lowermost wafer sheetlayer.

This practice will afford the advantage that irregular leading edges ofthe wafer sheets will not result in a shifting of the wafer sheetjoints.

According to another feature of the invention, the trailing edges of thewafer sheets are registered by the sensors and the wafer sheetsremaining in respective waiting positions are dropped, preferably at thesame time, when the last sensor has registered the trailing edge of awafer sheet for the first, lowermost wafer sheet layer whereas all othersensors have previously registered that trailing edge.

In that variant of the process, any irregularity of the traling edges ofthe wafer sheets will not influence the formation of the wafer laminate.

Another variant of the process according to the invention ischaracterized in that the wafer sheets supplied for the first, lowermostwafer sheet layer are moved in succession past sensors arranged ingroups, which are associated with respective waiting positions for thewafer sheets of the additional wafer sheet layers.

In that process variant an irregularity of the edges of the wafer sheetsfor the first, lowermost wafer sheet layer can be taken into account sothat the deposition of the wafer sheets in all additional wafer sheetlayers to the adjacent composition layer will not be influenced by suchirregularity.

In accordance with the invention the leading edges of the wafer sheetsmay be registered by sensors and a wafer sheet remaining in its waitingposition may be dropped when one sensor of the group associated withthat waiting position registers as the first sensor the leading edge ofa wafer sheet for the first, lowermost wafer sheet layer.

Alternatively, the trailing edges of the wafer sheets may be registeredby sensors and a wafer sheet remaining in waiting position may bedropped only when the last sensor of the group associated with thatwaiting position registers the trailing edge of a wafer sheet for thefirst, lowermost wafer sheet layer whereas all remaining sensors of thatgroup have previously registered that trailing edge.

According to another feature of the invention the wafer sheets for theadditional wafer sheet layers, which wafer sheets remain in respectivewaiting positions, are dropped at the same time as soon as the sensorregisters an edge of one of the wafer sheets for the first, lowermostwafer sheet layer.

As a result, those wafer sheets which in any additional wafer sheetlayer succeed the wafer sheets which have previously been applied to theadjacent composition layer will be applied to that composition layer atthe same time.

The invention provides apparatus which serves to carry out the processand comprises a conveyor belt for the wafer laminate, the first,lowermost wafer sheet layer of which lies on said conveyor belt, and aplurality of coating heads, which succeed each other in the direction ofconveyance and are disposed above said conveyor belt and serve to applyrespective composition layers to respective wafer sheet layers of thewafer laminate, and pressure roller for acting on respective wafer sheetlayers of the wafer laminate, which pressure rollers preferably succeedrespective coating heads. That apparatus is characterized in that theconveyor belt is preceded by a primary feeder which is provided with atleast one sensor and serves to supply the wafer sheets of the first,lowermost wafer sheet layer, a wafer sheet applicator for applying wafersheets of each additional wafer sheet layer to the adjacent compositionlayer succeeds each coating head and precedes each pressure rollersucceeding said coating head, in the direction of conveyance, saidapplicator comprises a waiting position for the wafer sheets and a wafersheet feeder for feeding successive wafer sheets to the waiting positionand, if desired a common conveyor line for supplying the wafer sheets ofall additional wafer sheet layers of the wafer laminate is provided andis common to the wafer sheet feeders of all wafer sheet applicators andpreferably forms a wafer sheet supply, and the conveyor line and theprimary feeder are preferably connected to common wafer sheet supplymeans.

This design according to the invention ensures that in response to thesignals delivered by one or more sensors for detecting the wafer sheetedges each of the wafer sheet applicators will apply a wafer sheet tothe adjacent composition layer when the trailing edge of the precedingwafer sheet has just moved past the waiting position of the wafer sheetapplicator and that each wafer sheet which has been applied to thecomposition layer will immediately be forced against said compositionlayer under constant pressure.

If the apparatus according to the invention comprises a common conveyorline for all wafer sheet feeders of the several wafer sheet applicators,the wafer sheets for all additional wafer sheet layers may becontinually supplied from one or more wafer-baking ovens. Saidwafer-baking ovens may differ from those which supply the wafer sheetfor the first, lowermost wafer sheet layer.

Alternatively, the conveyor line leading to the wafer sheet feeders ofthe wafer sheet applicators and the primary feeder for supplying thewafer sheets of the first, lowermost wafer sheet layer may be connectedto common wafer sheet supply means. That design will be particularlydesirable if the wafer sheets for all wafer sheet layers from one ormore wafer-baking ovens are combined on a single conveyor line beforebeing used in making a wafer laminate.

According to a further feature of the invention, the wafer sheetapplicator comprises lateral guide bars, which are preferably providedin the wafer sheet feeder and define the position of the wafer sheets inthe waiting position, a forward stop, which succeeds the wafer sheetfeeder and defines the waiting position in the direction of conveyance,and a wafer sheet-depositing device, which moves each wafer sheet fromthe waiting position to the adjacent composition layer.

That design ensures that each wafer sheet in a waiting position will beprecisely arranged relative to the adjacent composition layer of thewafer laminate so that each of the wafer sheets which are successivelyapplied by the wafer sheet applicator to the same composition layer willhave the same position relative to the composition layer.

According to a further feature of the invention the wafersheet-depositing device comprises two fingers or retaining plates or thelike, which support the wafer sheets in waiting position above theadjacent composition layer and which can be pulled out of the region ofthe waiting position across the direction of conveyance of the conveyorbelt.

This feature will result in a particularly simp design of the wafersheet-depositing device, which requires only such a small space that itcan be disposed very close to the adjacent composition layer.

To permit an exact adjustment of each waiting position and of the offsetwhich is desired in each case, a feature of the invention resides inthat the forward stop extends across the direction of conveyance of theconveyor belt and is adjustable in the direction of conveyance.

To permit an exact lateral positioning of each wafer sheet in itswaiting position it is a feature of the invention that the lateral guidebars are movable from a receiving position, in which their spacingacross the direction of conveyance exceeds the corresponding dimensionof the wafer sheet, to a locating position, in which their spacingacross the direction of conveyance is substantially as large as thecorresponding dimension of the wafer sheet and in which the lateralguide bars locate the sides of the wafer sheets in the waiting position.

To ensure that the wafer sheets in the waiting position will be exactlylocated in the direction of conveyance, it is a feature of the inventionthat the forward stop and the rear stop are movable from a receivingposition, in which their spacing in the direction of conveyance exceedsthe corresponding dimension of the wafer sheet, to a locating position,in which their spacing in the direction of conveyance is substantiallyas large as the corresponding dimension of the wafer sheets and in whichthe stops locate the ends of the wafer sheets in the waiting position.

According to a further feature of the invention, the lateral guide barsare provided with projections, which extend laterally below the wafersheets which remain in the waiting position, the lateral guide bars arepivoted on axes which are parallel to the direction of conveyance, andthe wafer sheet-depositing device is formed by the pivoted lateral guidebars.

According to another feature of the invention the pressure roller whichsucceeds the wafer sheet applicator has a peripheral velocity whichexceeds the velocity at which the wafer laminate is conveyed. Owing tothat design, a gap formed between two consecutive wafer sheets as theyare deposited on the adjacent composition layer will be closedimmediately after the application of the wafer sheet and before thelatter has been entirely forced onto the composition layer. This resultcan also be achieved by another feature of the invention, which residesin that a spiked roller is provided which succeeds the wafersheet-depositing device and is engageable with the applied wafer sheetand preferably comprises only one row of spikes.

According to another feature of the invention the pressure applied bythe pressure roller to superimposed wafer sheet edges of consecutivewafer sheets overcomes the local strength of the wafer sheet edges.Owing to that design any doubling of the edges of two consecutive wafersheets of a wafer sheet layer will be eliminated in that the wafer sheetedges are compressed to substantially one wafer sheet thickness so thatany wafer sheet applied in a wrong position will not disturb thestructure of the bond-type wafer laminate.

Also in accordance with the invention the primary feeder comprises atransport belt, which precedes the conveyor belt, a lateral guide forthe wafer sheets is disposed above the transport belt and is laterallyoffset along the transport belt from the path of the complete waferlaminate and extends over the conveyor belt, that portion of the lateralguide which extends above the conveyor belt carries a wedge, whichprotrudes laterally into the path of the wafer sheets and has across thedirection of conveyance a dimension which corresponds to the lateraloffset of the path of the wafer sheets on the transport belt from thepath of the complete wafer laminate on the conveyor belt, and at leastone sensor is disposed above the path of the wafer sheet cornersadjacent to the lateral offset thereof. If a wedge is provided whichprotrudes into the path of the wafer sheets which adjoin at theiradjacent edges, the wedge surface will control the velocity at which thewafer sheets moving past the wedge are displaced across the direction ofconveyance, and the extent of the wedge across the direction ofconveyance will determine the extent of the displacement of the wafersheets across the direction of conveyance. As a result, the path of thewafer sheets before the wedge can be offset from the path of thecomplete wafer laminate to such an extent that the lateral displacementof the adjoining wafer sheet edges which is due to the offset issufficient to ensure a reliable detection of the wafer sheet edges byone or more sensors.

Also in accordance with the invention the primary feeder comprises threeconsecutive conveyors, which precede the conveyor belt, the second ofsaid conveyors in the direction of conveyance has the same velocity ofconveyance as the conveyor belt, the two other conveyors have highervelocities of conveyance, at least one holding-down roller for the wafersheets is disposed at least above the second conveyor and above theconveyor belt, the holding-down roller of the second conveyor brakes thewafer sheets so that a queue of wafer sheets will be formed on the firstconveyor, and at least one sensor is provided between the holding-downroller of the second conveyor and the holding-down roller of theconveyor belt. Owing to that design of the apparatus according to theinvention the second conveyor will brake each wafer sheet so that thewafer sheets on the first conveyor will be pushed together so that theyform a queue of wafer sheets and their edges engage, the first wafersheet conveyor moves under said queue of wafer sheets, and each wafersheet transferred from the second conveyor to the third conveyor isaccelerated by the latter, which moves at a higher velocity, so that agap is opened between that wafer sheet and the next following wafersheet, which is still on the second conveyor. Said gap permits an exactregistering of the wa er sheet edges defining the gap by the sensor orsensors. The third conveyor then delivers each wafer sheet directly tothat conveyor belt above which the several coating heads are arranged.Since the third conveyor has a higher velocity of conveyance than theconveyor belt, the several wafer sheets which have moved past thephotoelectric detector will be pushed together so that their edgesengage because the wafer sheets are braked by the conveyor belt. Thiswill result in a wafer sheet layer in which the edges of the wafersheets adjoin each other. Because the second conveyor and the conveyorbelt have the same velocity of conveyance, it is ensured that a gapbetween two consecutive wafer sheets will always be formed adjacent tothe second and third conveyors and will be closed adjacent to the thirdconveyor and the conveyor belt.

According to a further feature of the invention the primary feedercomprises a conveyor which precedes the conveyor belt and defines forthe wafer sheets a conveyor path which is vertically offset from theconveyor path of the conveyor belt, and at least one sensor is providedin the region of the vertical offset. The gap which is due to thevertical offset is of special advantage with sensors consisting ofphotoelectric detectors.

For another variant of the formation of a gap between two consecutivewafer sheets, it is a feature of the invention that the primary feedercomprises a conveyor which precedes the conveyor belt and defines forthe wafer sheets a conveyor path which extends in the same plane as andat an angle to the conveyor path of the conveyor belt, and at least onesensor is provided adjacent to the adjoining ends of the conveyor beltand wafer sheet conveyor.

To permit a detection of the wafer sheet edges even when no gap isformed between consecutive wafer sheets, it is a feature of theinvention that the primary feeder comprises a conveyor which precedesthe conveyor belt, a roller is provided, which extends across thedirection of conveyance and is disposed between the conveyor belt andsaid conveyor and is adapted to be pivotally moved out of their commonplane of conveyance, and at least one sensor is provided adjacent to thepivoted roller.

An alternative feature of the invention resides in that the primaryfeeder comprises a conveyor which immediately precedes the conveyor beltand consists of a plurality of parallel spaced apart round belts, aroller is disposed between said round belts and movable at right anglesto the plane of conveyance of the round belts, and at least one sensoris provided adjacent to the movable roller.

According to the invention a mechanically operable sensor consists of apreferably spring-loaded pin, which is adapted to be displaced by thewafer sheet edge and actuates an electric switch.

According to a further feature of the invention the displaceable pin issecured to a rotary shaft, which extends across the direction ofconveyance.

A further feature of the invention resides in that the sensor consistsof a photoelectric detector, which extends at right angles to the pathof conveyance of the wafer sheets. This will be of advantage withphotoelectric detectors having a light path extending through the gapbetween two consecutive wafer sheets.

According to a further feature of the invention the sensor consists of aphotoelectric detector which extends at an acute angle to the path ofconveyance for the wafer sheets. With that design the wafer sheet edgewill be detected over a substantial part of its length andirregularities will be compensated.

According to a further feature of the invention, a plurality of sensorsare provided adjacent to the wafer sheet edges to be detected and thesensors are arranged in succession in the direction of conveyance.

These sensors may be arranged in accordance with the spacing of thewafer sheet joints in the respective wafer sheet layers so that thespacing of the wafer sheet joints in one wafer sheet layer can bealtered relative to the spacing in the first, lowermost wafer sheet edgein that the distance from the sensor associated with that wafer sheetlayer to the sensor associated with the first, lowermost wafer sheetlayer is increased. If the positions of the coating heads cannot bechanged, the positions of the several sensors can be so adjusted that anexact register of the wafer sheet joints in the several wafer sheetlayers can be ensured.

According to a further feature of the invention, a plurality of sensorsare provided adjacent to the wafer sheet edges to be registered and thesensors are laterally spaced apart.

IF the sensors are only laterally spaced apart, each wafer sheet edge isdetected at the same time by all sensors of a row which is transverse tothe direction of conveyance. As a result, a wafer sheet edge will bereliably detected even if it has been broken out to some extent adjacentto one of the sensors, which will then detect that wafer sheet edge sometime before the other sensors. If the signal from said sensors triggersthe operation of a wafer sheet applicator only when at least two sensorsdeliver a signal at the same time the broken out wafer sheet edge willnot influence the spacing of the wafer sheet joints in the associatedwafer sheet layer.

To permit a separate adjustment of the time at which a wafer sheet isdeposited by each wafer sheet applicator, it is a feature of theinvention that a plurality of sensors are provided adjacent to the wafersheet edges to be registered and at least one sensor is provided foreach wafer sheet applicator.

According to a further feature of the invention the distance from onewafer sheet applicator and particularly its forward stop one or moresensors associated with that wafer sheet applicator and belonging to theprimary feeder is an integral multiple of the length of a wafer sheet inthe direction of conveyance. That design is particularly desirable inthe making of wafer blocks and can be used if the sensors are arrangedin accordance with the spacing of the wafer sheet joints of theassociated wafer sheet layer.

A further feature of the invention resides in that the distance from awafer sheet applicator, particularly its forward stop to one or moresensors of the primary feeder is an integral multiple of the length of awafer sheet in the direction of conveyance less the distance by whichthe wafer sheets associated with that wafer sheet applicator are offsetfrom those of the first, lowermost wafer sheet layer. This will beparticularly desirable if a wafer sheet edge is registered by one sensoror by sensors which are juxtaposed across the direction of conveyanceand the resulting signal is used to trigger all wafer sheet applicators.

BRIEF DESCRIPTION OF THE DRAWING

The invention will now be explained more in detail and by way of examplewith reference to illustrative embodiments of apparatus according to theinvention, which are shown in the drawings, in which FIG. 1 is adiagrammatic side elevation showing an embodiment of apparatus accordingto the invention, FIG. 2 is a diagrammatic side elevation showing adetail of FIG. 1, FIG. 3 is a top plan view showing another embodimentof apparatus according to the invention, FIGS. 4 and 5 are,respectively, a top plan view and elevation showing an embodiment of thewafer sheet applicator, FIGS. 6 and 7 are side elevations showingrespective additional embodiments of a wafer sheet applicator, FIGS. 8and 9 are top plan views showing respective details of the primaryfeeder, FIG. 10 is a side elevation showing an additional embodiment ofa wafer sheet applicator and FIGS. 11 to 17 show different embodimentsof the primary feeder provided according to the invention for the wafersheets of the first, lowermost wafer sheet layer.

The illustrative embodiment of apparatus according to the inventionshown in FIG. 1 for making a wafer laminate comprising a primary feeder1 for supplying wafer sheets to a conveyor belt 2. A plurality ofcoating heads 3 are provided along the conveyor belt and succeeded byrespective wafer sheet applicators 4. In the embodiment shown by way ofexample only two coating heads 3 succeeded by respective wafer sheetapplicators 4 are shown and are used to make a wafer laminate consistingof three wafer sheet layers and two intervening composition layers. Itwill be understood that more coating heads 3 may be provided independence on the number of wafer sheet layers of a wafer laminateconsisting of a larger number of layers.

The coating heads 3 may consist of so-called contacting coating heads orof film-applying coating heads. All known designs of such coating headsmay be used.

Each coating head 3 is succeeded by a wafer sheet applicator 4, whichcomprises a wafer sheet feeder 5, a waiting position for the wafersheets, a wafer sheet-depositin device 6 and a pressure roller 7, whichsucceeds the device 6. The individual wafer sheets are supplied to thewafer sheet feeder 5 of a given wafer sheet applicator 4 via a conveyorline 8, which has a deflector 9 for the first wafer sheet feeder 5. Theconveyor line bridges the coating head and the wafer sheet applicator.The wafer sheet feeder 5 bridges the difference in height between theconveyor line 8 and the wafer sheet depositing device 6. At thebeginning of the apparatus shown in FIG. 1, a swivel deck 10 isprovided, by which the several wafer sheets coming from wafer sheetsupply means which are not shown are delivered to the primary feeder 1or to the conveyor line 8.

FIG. 2 shows that portion of FIG. 1 which comprises the primary feeder 1and the first coating head 3. The coating head 3 shown in FIG. 2 is afilm-type coating head for caramel-like compositions. In that coatinghead the composition to be applied is delivered by a feed hopper 12 to acoating roller 11 and is scraped off by a knife 13 and deposited by saidknife onto the moving strip of adjoining wafer sheets 14 movingunderneath. The conveyor belt 2 is preceded by the primary feeder 1,which consists of a first conveyor 15, a second conveyor 16 and a thirdconveyor 17, which succeed each other in that order in the direction ofconveyance. A photoelectric detector 18 is provided in the transferregion between the second conveyor 16 and the third conveyor 17. Twopressure rollers 19 are provided above the second conveyor 16 and ensurethat the wafer sheets lying on the second conveyor 16 will actually moveonly at the velocity of conveyance of the second conveyor. For the samepurpose, a pressure roller 20 is provided above the third conveyor 17and a pressure roller 21 is provided above the conveyor belt 2.

The first conveyor 15 and the third conveyor 17 are operated at the samespeed, which exceeds the speed of the second conveyor 16 and of the beltconveyor 2, which always revolve at the same speed. The three conveyors15, 16 and 17 may consist of endless conveyor belts, which extendthroughout the width of the path of the wafer sheets 14, or may consistof a plurality of narrow conveyor belts, which are juxtaposed across thedirection of conveyance.

FIG. 3 shows another embodiment of the primary feeder 1 and thesucceeding film-type coating head 1. To clarify the representation, thecoating roller 11 and the scraping knife 13 are the only parts of thefilm-type coating head which are shown. In this embodiment of theprimary feeder 1, a guide bar 22 is attached laterally of the path ofthe wafer sheets 14 and at its forward end in the direction ofconveyance is provided with a wedge 23, which protrudes into the path ofthe wafer sheets. The guide bar 22 extends along a conveyor belt 24,which precedes the conveyor belt 2. The guide bar 22 protrudes above theconveyor belt 2. The wedge 23 is disposed above the upper course of theconveyor belt 2. A photoelectric detector 25 is disposed in the spacebetween the conveyor belt 24 and the conveyor belt 2 adjacent to theedge of the wafer sheets 14 lying on the conveyor belt 2. Thephotoelectric detector 25 registers the end edge of each wafer sheet asit moves under the photoelectric detector, specifically that portion ofthe trailing edge of the preceding wafer sheet which protrudes laterallybeyond the succeeding wafer sheet 14. A plurality of sensors 25', 25"spaced apart in the direction of conveyance may be provided above thepath of the corners of the wafer sheets and serve to register thatportion of the edge of the wafer sheet 14 lying on the conveyor belt 2which protrudes beyond the succeeding wafer sheet 14.

The wafer sheet-depositing device 6 shown in FIGS. 4 and 5 consists oftwo fingers 26, which support the wafer sheet 14 in waiting positionbefore it is deposited. These fingers are secured to finger carriers 27,which are mounted on slide tracks 28 and slidable thereon across thedirection of conveyance. For a displacement of the two finger carriers27 across the direction of conveyance of the wafer sheets 14, a lever ispivoted to each finger carrier 27 and is eccentrically connected to acircular disc 29. To reciprocal the finger carriers, the circular disc29 is rotated by a fluid-operated cylinder 30, which is connected to aneccentric disc 31, which is non-rotatably connected to the circular disc29.

The wafer sheet-depositing device 6 has a forward stop 31 for engagementby each wafer sheet 14 which is sliding along the wafer sheet feeder 5and is supported by the fingers 26. The forward stop 31 may be formed,e.g., by the rear wall of the housing of the wafer sheet-depositingdevice 6 or of a bar which is adjustable in the direction of conveyance.The wafer sheet 14 is guided on its sides in the wafer sheet feeder 5and in waiting position lies on the fingers 26 and engages the forwardstop 31. This ensures an exact alignment of the wafer sheet 14 with theconveyor 2 and the path of the wafer laminate.

One or more compressed-air nozzles 32 (see FIG. 1) may be provided abovethe fingers 26 and in front of the stop 31, i.e., above the waitingposition of the wafer sheets 14, and may serve for a fast and controlleddescent of each wafer sheet 14. These nozzles 32 are supplied withcompressed air only for short times as the fingers 26 are pulled apart.

The waiting position of the wafer sheet 14 lying on the fingers 26 inthe wafer sheet applicator 6 is defined in the direction of conveyanceby the forward stop 31 and parallel to the direction of conveyance maybe defined by lateral guide bars 36, which extend parallel to thedirection of conveyance and can be adjusted transversely to thatdirection.

When the apparatus shown in FIG. 1 is to be used to make a bond-typewafer sheet laminate, the individual wafer sheets coming from wafersheet supply means, e.g., a wafer sheet cooler (not shown) or the like,are supplied via the swivel deck 10 to the first conveyor 15 of theprimary feeder 1 and are forwarded by the primary feeder to the conveyorbelt 2, on which the end edges of the wafer sheets adjoin, and areprovided with a composition layer by the first coating head 3 andsubsequently conveyed to the first wafer sheet applicator 4. The wafersheets for the second wafer layer are supplied from the swivel deck 10via the conveyor line 8 and the deflector 9 to the wafer sheet feeder 5of the first wafer sheet applicator 4 so that they lie in waitingposition on the fingers 26 and are subsequently deposited on the firstcomposition layer. For this purpose the wafer sheet-depositing device 6is operated so that the fingers 26 are pulled apart across the directionof conveyance and the wafer sheet 14 is dropped. The resulting portionof the wafer laminate is moved to the second coating head 3 under thesucceeding pressure roller 7, which forces the second wafer sheet layeragainst the composition layer. The second coating head 3 applies asecond composition layer to the second wafer sheet layer. The wafersheet layers 14 of the third wafer sheet layer are also supplied via theconveyor line 8 to the wafer sheet feeder 5 of the second wafer sheetapplicator 4 and are then applied like the second wafer sheet layer andsubsequently forced down by a pressure roller 7. Behind that pressureroller 7, the complete bond-type laminate of wafer sheets, comprisingthree wafer sheet layers, lies on the conveyor belt 2.

If the photoelectric light detector 18 or 25 measures the trailing edgeof the last of the adjoining wafer sheets 14 of the lowermost wafersheet layer, the distance from the forward stop 31 of each wafersheet-depositing device 6 to the photoelectric detector 18 or 25 equalsan integral multiple of the dimension of the wafer sheet in thedirection of conveyance less the distance by which the wafer sheet jointof the wafer sheet layer that is to be formed is offset from the wafersheet joints of the lowermost wafer sheet layer. In such apparatusaccording to the invention the wafer sheets are deposited by all wafersheet-depositing devices 6 at the same time and the offset will bedetermined by the location of the wafer sheet applicator 4. To permit anadjustment of that offset, each wafer sheet applicator 4 is adjustablealong the conveyor belt 2 in the direction of conveyance to an extentwhich corresponds to one wafer sheet length, i.e., to the length of onewafer sheet in the direction of conveyance. The wafer sheet-depositingdevices 6 are triggered by a signal from the photoelectric detector 18or 25 when the trailing edge of the preceding wafer sheet 14 is spacedsuch a distance from the respective forward stop 31 that the timerequired for the travel of the trailing edge to the stop 31 correspondsto the time required for the fall of the wafer sheet 14 to thecomposition layer so that the leading edge of the wafer sheet 14 willlie immediately behind the trailing edge of the preceding wafer sheet14.

Alternatively, the distance from each wafer sheet applicator 4 or fromthe forward stop 31 of each wafer sheet-depositing device 6 to thephotoelectric detector 18 or 25 may be selected independently of amultiple of the wafer sheet length. In that case the offset of the wafersheet joints in each wafer sheet layer from those in the lowermost wafersheet layer is adjusted by a delay of the signal coming from thephotoelectric detector 18 or 25.

For the supply of wafer sheets to the wafer sheet feeders 5 of the wafersheet applicators 4, a supply of wafer sheets is maintained on theconveyor line 8. For instance, a queuing zone is formed before eachwafer sheet feeder 5 as in the primary feeder 1 and a wafer sheet isconveyed from the queuing zone to the wafer sheet feeder whenever thepreceding wafer sheet previously held in position in the wafer sheetfeeder 5 by a brush 35 or the like has been delivered from the wafersheet feeder 5 to the waiting position in the wafer sheet-depositingdevice 6 after the wafer sheet which had been in the waiting positionhas been deposited on the composition layer. The wafer sheet which hasbeen conveyed by the conveyor line 8 into the wafer sheet feeder 5 isheld by the brush 35 in a ready position before arriving at the waitingposition in the wafer sheet-depositing device 6.

It will be understood that the wafer sheets required for each wafersheet layer need not be diverted via the swivel deck 10 from the wafersheets which are being supplied to the lowermost wafer sheet layer butmay be supplied directly to the respective wafer sheet applicator, e.g.,from other wafer-baking ovens. For instance, each wafer sheet layer maybe assembled from wafer sheets coming from a different wafer-bakingoven.

The above and subsequent description will be analogously applicable tothe making of an endless wafer laminate of consecutive wafer blockswhich are continuously assembled with adjoining end faces and which areinterconnected, if desired, by composition webs forming at the buttjoints and are otherwise connected only by the composition layers. Inthat case the offset of the wafer sheets 14 in each additional wafersheet layer from the wafer sheets 14 of the first, lowermost wafer sheetlayer is zero.

In a variant of the process according to the invention, each wafer sheet14 is deposited on the adjacent composition layer so as to leave a gapbehind the preceding wafer sheet 14 and is then displaced until itengages the preceding wafer sheet. For this purpose each wafersheet-depositing device 6 is triggered slightly later so that theleading edge of the wafer sheet 14 is spaced from the trailing edge ofthe preceding wafer sheet 14. The pressure roller 7 which succeeds thewafer sheet-depositing device 6 is driven at a peripheral velocity whichslightly exceeds the velocity which would correspond to the velocity ofconveyance of the wafer laminate. As a result, the wafer sheet 14 ispushed by the pressure roller 7 into engagement with the preceding wafersheet 14. As a result, the gap formed between two successive wafersheets is closed. This is also applicable to a gap which mayinadvertently form as a result of differences in length between thewafer sheets (FIG. 7). Alternatively, a spiked roller 33 may be providedbehind the wafer sheet-depositing device 6 and in front of the pressureroller 7 and may preferably have only a single row of spikes 34, whichpenetrate into the upper surface of the wafer sheet 14 that has beendeposited on the composition layer by the wafer sheet-depositing device6. As a result, the spiked roller 33 pushes that wafer sheet on thecomposition layer in the direction of conveyance into engagement withthe preceding wafer sheet 14 so that the gap between the two wafersheets 14 is closed and the edges of the wafer sheets which constitutethe resulting wafer sheet layer adjoin.

As is shown in FIGS. 8 and 9, a plurality of sensors may also beprovided at the primary feeder 1 for feeding the wafer sheets 14 for thefirst, lowermost wafer sheet layer. In the variant shown in FIG. 8, aspace is left between the second conveyor 16 and the third conveyor 17and three photoelectric detectors 18, 18', 18" are provided in thatspace. Said detectors include two sensors 18, 18", which are disposed atrespective paths of corners of the wafer sheets, and one detector 18' isdisposed adjacent to the middle of the path of the wafer sheet 14. Thethree photoelectric detectors 18, 18', 18" are arranged in a row, whichextends across the direction of conveyance, so that the detectors detecta wafer sheet edge at the same time.

In the embodiment shown in FIG. 9 the photoelectric detectors 18, 18',18" are disposed above the second conveyor 16 behind the holding-downroller 19 and above the third conveyor 17 and each photoelectricdetector registers the wafer sheet edge lying on the associated conveyorbelt.

The photoelectric detectors which are juxtaposed across the direction ofconveyance are offset in the direction of conveyance so that each wafersheet 14 moves past the photoelectric detectors 18, 18', 18" insuccession. A wafer sheet applicator 4 is associated with eachphotoelectric detector and will be triggered when a wafer sheet edge ismoving past the associated photoelectric detector.

The sensors for detecting the edges of the wafer sheets of the first,lowermost wafer sheet layer may be spaced apart in and across thedirection of conveyance so that the sensors are arranged in a pluralityof rows, which are spaced apart in the direction of conveyance and eachof which comprises a plurality of juxtaposed sensors. In such anarrangement each row preferably comprises at least three photoelectricdetectors and the number of rows depends on the number of wafer sheetapplicators. The region covered by these sensors arranged in rows mayextend from the holding-down roller 19 of the second conveyor 16 overthe third conveyor 17 to the holding-down roller 21 of the conveyor belt2 because there will always be a gap between two consecutive wafersheets throughout said region.

In accordance with the invention the gap formed between two consecutivewafer sheets for the first, lowermost wafer sheet layers in order topermit the detection of the wafer sheet edges may alternatively beformed in that consecutive wafer sheets are offset in height.

For this purpose the conveyor belt 2 is preceded by a conveyor whichconveys the wafer sheets 14 on a path which is upwardly or downwardlyoffset, preferably by more than the thickness of a wafer sheet, from theplane of conveyance of the conveyor belt.

The gap resulting from an offsetting of the wafer sheets in height neednot be formed immediately before the conveyor belt but may be formed bymeans of two consecutive transport belts 38, 39 of the primary feeder 1,which are spaced a larger distance from the succeeding conveyor belt 2,opposite to the direction of conveyance. The distance from the pointwhere the gap is formed to the conveyor belt 2 may be bridged by thesecond transport belt 39 or by an additional transport belt.

In the illustrative embodiment shown by way of example in FIG. 11, theupper course of the second transport belt 39 is disposed above the uppercourse of the first transport belt 38.

In the illustrative embodiment shown in FIG. 12, the wafersheet-conveying path of the second transport belt is disposed below thefirst transport belt 38.

Another variant of the means for forming the gap is shown in FIG. 13. Inthat variant the second transport belt 39 extends at a small angle tothe first transport belt 38 so that a wedge-shaped gap betweenconsecutive wafer sheets will form in the transfer region between thetwo transport belts. That wedge-shaped gap is closed on the secondtransport belt 39 by a pressure roller, which revolves slightly fasterthan the second transport belt. It will be understood that the secondtransport belt may be constituted by the conveyor belt 2.

For a reliable detection of the wafer sheet edges it is not essential toform between two consecutive wafer sheets a gap extending across thedirection of conveyance throughout the dimension of the wafer sheetwhich is transverse to the direction of conveyance. If the wafer sheetsadjoin in a row, it will be sufficient to lift each wafer sheet on oneside for a short time so that it will be pivotally moved on an axiswhich extends in the direction of conveyance and the edge of thepivotally moved wafer sheet can then be registered.

The pivotal movement can be imparted to the wafer sheet by a roller 40,which is disposed between two conveyors 38, 39 and protrudes above theplane of conveyance or can be pivotally moved to such position so thateach wafer sheet moving past the roller 40 will be pivotally moved outof the plane of conveyance (FIG. 14).

If conveyors consisting of round belts 41 are used, a roller 42 isprovided between the round belts 41 and said roller can be lifted aboveand lowered below the path of conveyance of the wafer sheets by means ofa pneumatic cylinder (not shown) or the like. The displacement of theroller 42 is controlled by a counting wheel 43, which measures thelength of the wafer sheet in the direction of conveyance. This willensure that each wafer sheet will be turned out of the plane ofconveyance only once (FIG. 15). That roller may be stationary if itprotrudes above the plane of conveyance and lifts one side of each wafersheet as it moves past the roller.

The primary feeder 1 shown in FIG. 2 forms by means of the thirdconveyor 17 a gap between two consecutive wafer sheets immediatelybefore the conveyor belt 2 and may be spaced a larger distance from theconveyor belt 2 opposite to the direction of conveyance. That variantdiffers from that shown in FIG. 2 only in that the conveyor belt 2 isreplaced by a fourth conveyor 44.

The primary feeder shown in FIG. 17 differs from the one shown in FIG. 3only in that the conveyor belt 2 has been replaced by a second conveyor39.

The sensors for registering the wafer sheet edges may consist ofspring-loaded pins, which are adapted to be displaced by the associatedwafer sheet edge and actuate an associated electric switch. These pinsmay be secured to shafts, which extend across the direction ofconveyance and are rotated by each wafer sheet to move the pins out ofthe paths of the wafer sheet.

Alternatively, the sensors may consist of clearance-dependentphotoelectric detectors, which extend preferably at right angles to thepath of the wafer sheets and above the same adjacent to the gap betweentwo successive wafer sheets or adjacent of the offset wafer sheet edges.These clearance-dependent photoelectric detectors detect only the wafersheet edges moving past the photoelectric detector at a certain distancetherefrom.

The sensors may alternatively consist of photoelectric detectors whichextend along the wafer sheet edge which is to be registered and extendat an acute angle to the path of conveyance of the wafer sheets and atright angles to the direction of conveyance and cover a larger length ofthe respective wafer sheet edge so that any broken-out portion of thewafer sheet edge will not affect the generation of the signal by thesensor.

In one embodiment of the invention the wafer sheet applicator 4 has awaiting position which is defined by two movable, lateral guide bars 36,a forward stop 31 and a rear stop 37. Each of the two lateral guide bars36 and of the two bars 31, 37 is reciprocable between a receivingposition and a locating position. The wafer sheet remaining in thewaiting position is located across the direction of conveyance by thelateral guide bars 36 in their locating position and in the direction ofconveyance by the two stops in their locating position. In the receivingposition, the spacings of the guide bars 36 and of the stops 31, 37exceed the respective dimensions of the wafer sheet.

The movable lateral guide bars 36 may have projection which extendlaterally under the wafer sheets remaining in the waiting position.

The lateral guide bars 36 constitute the wafer sheet-depositing deviceand are pivotally movable about axes which are parallel to the directionof conveyance.

The lateral guide bars 36 and the stops 31, 37 are so controlled thatthey engage the wafer sheet remaining in the waiting position until thefingers 26 are pulled apart or the guide bars 36 are pivotally moved todrop the wafer sheet. Thereafter the guide bars 36 and the stops 31, 37are moved apart to their receiving positions.

The sensors for registering the wafer sheet edges may desirably haverelative to each other an arrangement which agrees with the arrangementof the sensors in the wafer sheet-testing line adjacent to the wafersheet cooler. In that wafer sheet-testing line, e.g., three juxtaposedsensors are provided, which cause a defective wafer sheet to be rejectedunless all three sensors register the associated wafer sheet edge at thesame time. This agreement of the sensor arrangements ensures that eachsensor of the primary feeder for the wafer sheets of the first,lowermost wafer sheet layer will register a wafer sheet edge becausethat wafer sheet edge has already been registered by the sensor in thetesting line.

We claim:
 1. An apparatus for the continuous production of an endlesswafer sheet laminate of uniform width, which comprises a first,lowermost layer of consecutive rectangular wafer sheets and superposed,additional and alternating layers of coating composition and consecutiverectangular wafer sheets, the layers extending in a longitudinaldirection of the laminate and each one of the wafer sheets having aleading and a trailing edge extending transversely to said direction,the apparatus comprising(a) a conveyor belt for the wafer sheetlaminate, the conveyor belt moving in said direction and the first,lowermost layer of consecutive rectangular wafer sheets lying on theconveyor belt with the trailing and leading edges of the consecutivewafer sheets adjoining, (b) a primary feeder preceding said conveyorbelt in said direction and supplying the wafer sheets of the first,lowermost layer to the conveyor belt, the primary feeder including(1)sensor means sensing one of said edges of each one of the wafer sheetsof the first, lowermost layer, (c) a plurality of coating headssucceeding each other in said direction and disposed above said conveyorbelt for applying the composition layers to respective ones of the wafersheets, (d) a plurality of wafer sheet applicators for applying thewafer sheets of a respective one of the superposed, additional layers toan uncovered, underlying one of the layers of the coating composition ofa previously formed portion of the wafer laminate, the applicators beingdisposed above said conveyor belt and succeeding respective ones of thecoating heads in said direction, each one of the applicators(1) defininga station disposed above an uncovered uppermost one of said compositionlayers of the previously formed portion of the wafer laminate and beingarranged to drop a respective one of the wafer sheets at said stationonto the uncovered uppermost composition layer at a time determined bythe sensing of said one edge of a respective one of the wafer sheets ofthe first, lowermost layer by said sensing means, and (2) includes awafer sheet feeder for supplying successive ones of the wafer sheets ofthe superposed, additional layers to said station, and (e) a pluralityof pressure rollers disposed above the conveyor belt and succeedingrespective ones of the applicators in said direction for pressing therespective wafer sheets dropped onto the uncovered uppermost compositionlayers thereagainst.
 2. The apparatus of claim 1, further comprising acommon conveyor line for the wafer sheets of the superposed, additionallayers, the common conveyor line leading to the wafer sheet feeders ofall wafer sheet applicators for supplying the wafer sheets to theapplicators.
 3. The apparatus of claim 2, wherein the common conveyorline constitutes a wafer sheet storage for the wafer sheets of thesuperposed, additional layers.
 4. The apparatus of claim 2, furthercomprising a common wafer sheet supply supplying wafer sheets to theprimary feeder and the common conveyor line.
 5. The apparatus of claim1, wherein each applicator further comprises a wafer sheet depositingdevice including wafer sheet retaining means for retaining therespective wafer sheet in said station, the retaining means beingdisposed below said wafer sheet and above the uncovered uppermostcomposition layer, and being retractible transversely to said direction.6. The apparatus of claim 5, wherein each applicator further includes aspiked roller succeeding the wafer sheet depositing device in saiddirection and arranged to engage the wafer sheet dropped onto theuncovered uppermost composition layer.
 7. The apparatus of claim 6,wherein the spiked roller has a single row of spikes.
 8. The apparatusof claim 1, wherein each applicator further includes lateral guide barsextending in said direction and a forward stop extending transversely tosaid direction for defining said station for each one of the wafersheets to be dropped.
 9. The apparatus of claim 8, wherein the lateralguide bars form part of the wafer sheet feeder.
 10. The apparatus ofclaim 8, wherein the lateral guide bars are movable between a receivingposition and a locating position, the spacing between the guide barstransversely to said direction exceeding the length of said wafer sheetedges in the receiving position and said spacing corresponding to saidlength in the locating position, the guide bars exactly defining thelateral position of the respective wafer sheets in the locatingposition.
 11. The apparatus of claim 8, wherein the lateral guide barsare pivotal about axes extending parallel to said direction and includeprojections laterally subtending the respective wafer sheets in thelocating position, and the pivotal guide bars constituting a wafer sheetdepositing device moving each wafer sheet to the uncovered uppermostcomposition layer.
 12. The apparatus of claim 8, wherein said forwardstop is adjustable in said direction.
 13. The apparatus of claim 8,further comprising a rear stop defining said station at a rear endthereof.
 14. The apparatus of claim 13, wherein the stops are movablebetween a receiving position and a locating position, the spacingbetween the stops in said direction exceeding the extension of saidwafer sheet in said direction in the receiving position and said spacingcorresponding to said extension in the locating position, the stopsexactly defining the position of the respective wafer sheet in saiddirection in the locating position.
 15. The apparatus of claim 1,wherein the pressure rollers have a peripheral velocity exceeding theconveying speed of the conveyor belt.
 16. The apparatus of claim 1,wherein the primary feeder includes a transport device transporting thewafer sheets with the adjoining edges to the conveyor belt.
 17. Theapparatus of claim 16, further comprising a lateral guide for the wafersheets disposed above the transport device and extending therealong insaid direction, the lateral guide having a portion extending over theconveyor belt and defining a conveyor path for the wafer sheetslaterally offset from a conveyor path of the wafer sheets on theconveyor belt, the lateral guide portion carrying a wedge protrudinglaterally into the laterally offset path and displacing the wafer sheetswith the adjoining edges from the laterally offset path into the path ofthe wafer sheets on the conveyor belt, the wafer sheets forming a queueon the transport device before they form the first, lowermost layer, andat least one sensor disposed above the path of the wafer sheet cornersin the region of the lateral displacement of the wafer sheets with theadjoining edges for sensing any lateral displacement of the adjoiningedges relative to each other in the region of the wafer sheet corners.18. The apparatus of claim 16, wherein said transport device defines aconveyor path for the wafer sheets vertically offset from a path of thewafer sheets on the conveyor belt, and further comprising at least onesensor in the region of the vertical offset for sensing any adjoiningedges vertically offset relative to each other.
 19. The apparatus ofclaim 16, wherein the transport device defines a conveyor path for thewafer sheets coplanar with the conveyor path of the conveyor beltsupporting the wafer sheet laminate but disposed at an angle to saiddirection, the wafer sheets forming a queue on the transport devicebefore they form the first, lowermost layer, and at least one sensordisposed at facing ends of the transport device and the conveyor beltfor sensing the edges of the consecutive wafer sheets arranged at anangle to each other.
 20. The apparatus of claim 16, wherein thetransport device defines a conveyor path for the wafer sheetscorresponding to the conveyor path of the first, lowermost layer on theconveyor belt, the wafer sheets accumulating on the transport devicebefore they form the first, lowermost layer, further comprising a rollerdisposed between facing ends of the transport device and the conveyorbelt, the roller being pivotal transversely to said direction out ofsaid conveyor path, and at least one sensor in the region of the pivotalroller for sensing the edges of the consecutive wafer sheets.
 21. Theapparatus of claim 16, wherein the transport device includes a pluralityof parallel, spaced apart round belts defining a common plane ofconveyance for the wafer sheets, the wafer sheets forming a queue on thetransport device before they form the first, lowermost layer, furthercomprising a roller between the round belts and disposed perpendicularlymovably to the plane of conveyance, and at least one sensor in theregion of said roller for sensing the edges of the consecutive wafersheets.
 22. The apparatus of claim 1, wherein the primary feeder for thewafer sheets of the first, lowermost layer includes two consecutivetransport devices for transporting the wafer sheets with the adjoiningedges.
 23. The apparatus of claim 22, further comprising a lateral guidefor the wafer sheets disposed above the transport devices and extendingtherealong in said direction, the lateral guide defining a firstconveyor path for the wafer sheets along a first one of the transportdevices and having a portion extending over a second one of thetransport devices, the lateral guide portion carrying a wedge protrudinglaterally into the first conveyor path and laterally displacing thewafer sheets with the adjoining edges on the second transport deviceinto a second, laterally offset conveyor path, the wafer sheets forminga queue on the transport devices before they form the first, lowermostlayer, and at least one sensor disposed above the path of the wafersheet corners in the region of the lateral displacement of the wafersheets with the adjoining edges for sensing any lateral displacement ofthe adjoining edges relative to each other in the region of the wafersheet corners.
 24. The apparatus of claim 22, wherein the transportdevices define two vertically offset conveyor paths for the wafersheets, and further comprising at least one sensor in the region of thevertical offset for sensing the edges of vertically offset consecutivewafer sheets.
 25. The apparatus of claim 22, wherein the transportdevices define two coplanar conveyor paths for the wafer sheets disposedat an angle to each other, the wafer sheets forming a queue on thetransport devices before they form the first, lowermost layer, andfurther comprising at least one sensor disposed at facing ends of thetransport devices for sensing the edges of the consecutive wafer sheetsarranged at an angle to each other.
 26. The apparatus of claim 22,wherein the transport devices define two coplanar conveyor paths for thewafer sheets, the wafer sheets forming a queue on the transport devicesbefore they form the first, lowermost layer, further comprising a rollerdisposed between facing ends of the transport devices, the roller beingpivotal transversely to said direction out of said common conveyorpaths, and at least one sensor in the region of the pivotal roller forsensing the edges of the consecutive wafer sheets.
 27. The apparatus ofclaim 1, wherein the primary feeder comprises three consecutivetransport devices, an intermediate one of the consecutive transportdevices having the same velocity of conveyance as the conveyor belt andthe first and third consecutive transport devices having a velocity ofconveyance exceeding that of the conveyor belt, further comprising atleast one holding-down roller for the wafer sheets disposed above theintermediate transport device and the conveyor belt, the holding-downroller disposed above the intermediate transport device braking thewafer sheets coming from the first transport device to form a firstqueue of wafer sheets on the first transport device, and theholding-down roller disposed above the conveyor belt braking the wafersheets coming from the third transport device to form a second queue ofwafer sheets on the third transport device before the wafer sheets formthe first, lowermost layer, and at least one sensor disposed to sensethe edges of the consecutive wafer sheets in a gap formed between thefirst and second queues of the wafer sheets due to the difference in thevelocities of conveyance of the intermediate and third transportdevices.
 28. The apparatus of claim 27, comprising a plurality of saidholding-down rollers above the intermediate transport device and theconveyor belt, and said at least one sensor being disposed between alast one of said holding-down rollers above the intermediate transportdevice and a first one of said holding-down rollers above the conveyorbelt, in said direction.
 29. The apparatus of claim 1, wherein theprimary feeder comprises four consecutive transport devices, a secondand fourth one of the consecutive transport devices, in said direction,having the same velocity of conveyance as the conveyor belt and thefirst and third consecutive transport devices having a velocity ofconveyance exceeding that of the conveyor belt, further comprising atleast one holding-down roller for the wafer sheets disposed above thesecond and fourth transport devices, the holding-down roller disposedabove the second transport device braking the wafer sheets coming fromthe first transport device to form a first queue of wafer sheets on thefirst transport device, and the holding-down roller disposed above thefourth transport device braking the wafer sheets coming from the thirdtransport device to form a second queue of wafer sheets on the thirdtransport device before the wafer sheets form the first, lowermostlayer, and at least one sensor disposed to sense the edges of theconsecutive wafer sheets in a gap formed between the first and secondqueues of the wafer sheets due to the difference in the velocities ofconveyance of the second and third transport devices.
 30. The apparatusof claim 29, comprising a plurality of said holding-rollers above thesecond and fourth transport devices, and said at least one sensor beingdisposed between a last one of said holding-down rollers above thesecond transport device and a first one of said holding-down rollersabove the fourth transport device, in said direction.
 31. The apparatusof claim 1, wherein the sensor comprises a sensing pin displaceable bythe sensed wafer sheet edge and an electric switch actuated by thedisplaced pin.
 32. The apparatus of claim 31, further comprising arotary shaft extending transversely to said direction, the sensing pinbeing secured to the rotary shaft.
 33. The apparatus of claim 1, whereinthe sensor comprises a photoelectric detector extending perpendicularlyto the path of conveyance of the wafer sheets.
 34. The apparatus ofclaim 1, wherein the sensor comprises a photoelectric detector extendingat an acute angle to the path of conveyance of the wafer sheets.
 35. Theapparatus of claim 1, comprising a plurality of said sensors arrangedconsecutively in said direction.
 36. The apparatus of claim 1,comprising a plurality of said sensors laterally offset relative to eachother.
 37. The apparatus of claim 1, comprising a plurality of saidsensors laterally offset relative to each other laterally and spacedfrom each other in said direction.
 38. The apparatus of claim 1,comprising a plurality of said sensors, at least one of said sensorsbeing associated with each one of the wafer sheet applicators.
 39. Theapparatus of claim 38, wherein each sensor associated with a respectiveapplicator is spaced therefrom a distance corresponding to an integralmultiple of the extension of the wafer sheets in said direction.
 40. Theapparatus of claim 1, wherein the wafer sheets of the superposed,additional layers are offset in said direction from the wafer sheets ofthe first, lowermost layer, and comprising a plurality of said sensors,at least one of the sensors being associated with each one of the wafersheet applicators and each sensor associated with a respectiveapplicator is spaced therefrom a distance corresponding to an integralmultiple of the extension of the wafer sheets in said direction less theextent of the offset of the wafer sheets applied by the respectiveapplicator relative to the wafer sheets of the first, lowermost layer.41. The apparatus of claim 1, wherein each wafer sheet applicator isadjustable along the conveyor belt in said direction.